Appeal from the Circuit Court of Cook County. No. 01 CR 20265. Honorable Colleen McSweeney Moore, Judge Presiding.
 The opinion of the court was delivered by: Justice Karnezis
 Following a bench trial, defendant was convicted of first-degree murder (720 ILCS 5/9-1 (West 2000)) and was sentenced to 45 years' imprisonment; 25 years for murder with a mandatory 20-year add-on because the court found that defendant personally discharged a firearm during the commission of the murder (730 ILCS 5/5-8-1(a)(1)(d)(ii) (West 2000)). On appeal, defendant argues that: (1) the trial court erred when it denied his motion to quash arrest and suppress evidence; and (2) section 5-8-1(a)(1)(d)(ii) of the Unified Code of Corrections (730 ILCS 5/5-8-1(a)(1)(d)(ii) (West 2000)) violates the proportionate penalties clause as well as defendant's constitutional right to due process. We affirm.
 We discuss only those facts relevant to the disposition of this appeal. Prior to trial, defendant filed a motion to quash arrest and suppress evidence based on his warrantless arrest. At the hearing on defendant's motion, he argued that the police arrested him without probable cause. The following evidence was presented at the hearing.
 Defendant testified that on July 30, 2001, he was living at 1330 W. 13th Street in Chicago, with his wife. At approximately 11 a.m. on that date, two detectives who told defendant that they wanted to question him approached him. The detectives asked defendant to stay there until they called the homicide detectives. Defendant told the detectives that he wanted to leave. The detectives then handcuffed defendant.
 About 15 minutes later, another detective arrived. The detective put defendant in the back of a squad car and took him to a police station. At the police station, defendant made statements to an assistant State's Attorney. Defendant was never shown a warrant for his arrest.
 Detective Gregory Swiderek of the Chicago police department testified that on the evening of April 2, 2001, he and his partner, William Soregen, received an assignment regarding a homicide that had taken place in a parking lot at 1350 West 14th Street in Chicago. Upon arriving at the scene, Detective Swiderek learned that a woman named Kareen Goodwin had been shot to death in a car.
 On July 27, 2001, Detective Swiderek and other detectives were still investigating the shooting death of Goodwin. On that same date, Detective Swiderek interviewed Tony Robinson, who was in police custody. Robinson was being questioned regarding an unrelated murder. Detective Swiderek had a conversation with Robinson about the homicide of Goodwin. Robinson told Detective Swiderek that just before dark on the night Goodwin was killed, he was standing in the lobby of the building located at 1410 West 14th Street with Gregory Brown when he saw Maurice Lebon's blue four-door Chevy pass by. Brown asked Robinson if he wanted to "get" Lebon, meaning, to shoot Lebon. Robinson explained that Lebon was from a rival building and that Lebon owed Brown drug money. Robinson responded "no" and the two walked upstairs, where they ran into Antoine Truitt and an individual only known as "Boo*fn1 ." Brown asked Truitt and Boo if they wanted to come with him to "whack" Lebon. Brown, Truitt and Boo walked downstairs while Robinson went upstairs to use cocaine. About 10 minutes later, Robinson came down to the lobby, where he saw Brown, Truitt and Boo dressed in black. Brown showed Robinson a chrome .25-caliber semiautomatic pistol. Truitt and Boo also had guns in their pockets. Robinson went back upstairs and saw Truitt and Boo outside walking north to the parking lot near the row houses located just to the east. Robinson also saw Brown walk south. Robinson saw Lebon's car parked in the parking lot between the row houses. Robinson heard gunshots.
 A short while later, Brown returned and said, "I just whacked that n-----," meaning, that he shot Lebon. Brown also told Robinson that he put the gun in a garbage can by an incinerator. Robinson discovered that it was Goodwin that was killed inside Lebon's car. Robinson also told Detective Swiderek that he was not being entirely truthful because he was afraid of possible gang retaliation. Detective Swiderek told Robinson that he did not believe that Robinson was telling the whole truth because one of the persons Robinson claimed was involved in the shooting, Truitt, was dead at the time.*fn2
 On July 30, 2001, Detective Swiderek and Detective Soregen again spoke with Robinson. At that time, Robinson told the detectives that he had not been entirely truthful. He stated that Truitt was not with Boo and Brown the night Goodwin was killed, but that it was defendant who was there. He also stated that he was reluctant to name defendant because he knew defendant was a "general" in the New Breed Street gang. Robinson stated that everything else he previously told detectives was true. Robinson was then shown a photograph array and identified Boo, Brown and defendant as the individuals he saw on the night of the Goodwin murder.
 Detective Swiderek testified that no promises had been made to Robinson in exchange for the information he provided regarding the Goodwin murder. Detective Swiderek knew of no arrest warrant for defendant.
 Detective Vasilopoulos of the Chicago police department testified that on July 30, 2001, at approximately 3:30 p.m., he received a telephone call from youth investigator Battaglia. Battaglia had just seen defendant in the area of 13th and Racine in Chicago. Detective Vasilopoulos knew Robinson had identified defendant as being involved in Goodwin's murder. The detective drove to 13th Street and Racine Avenue but, before he arrived, he learned that youth investigator Battaglia had already stopped defendant.
 Detective Sanchez testified that on July 26, 2001, he arrested Robinson in relation to the murder of Phillip McKay. That day, Detective Sanchez had a conversation with Robinson regarding the murder of Goodwin. Robinson told him the names of the people involved in Goodwin's murder, but later changed his mind about the names. Robinson told Detective Sanchez that he could not tell him the real names because he was afraid if he named the persons who were really involved, his family would be harmed. Detective Sanchez testified that his report contained a narrative of his conversation with Robinson. Robinson told him that Brown, Boo and Truitt had killed Goodwin, but that was all he knew about the murder. Detective Sanchez went to Cook County jail the following day and interviewed Brown. Brown denied any involvement in the murder of Goodwin.
 After the hearing on defendant's motion to quash arrest and suppress evidence, the trial court denied the motion, finding that the evidence presented was sufficient to show that the police "had ample, overwhelming probable cause to believe that the defendant was involved in the murder in this case." Following ...