A multiweek drug investigation brought four arrests Tuesday, Delaware State Police spokeswoman Master Cpl. Heather Pepper said.

Jaquell McDonald, 25, of Dover; Shakiel Carter, 27, of Dover; Jahida Evans, 20, of Frederica; and Matthew Brown, 22, of Frederica, were all taken into custody and charged with felony offenses, authorities said.

Police said Mr. McDonald was stopped while driving and taken into custody without incident. According to authorities, he allegedly threw approximately 28.5 grams of crystal meth out his window prior to being contacted. A vehicle search also brought the discovery of $2,542 in suspected drug proceeds, police said.

A subsequent search warrant at a residence on Lady Court, Dover, led to the discovery of approximately 104.75 grams of crystal meth and drug paraphernalia. Ms. Carter was taken into custody at the residence without incident.

A search warrant was also conducted at a residence in the 100 block of Maple Drive, Frederica, where police recovered several rounds of ammunition, an extended magazine, a 9 mm handgun, drug paraphernalia, an ounce of marijuana and approximately $1,598 in suspected drug proceeds. Ms. Evans and Mr. Brown were located at the residence and taken into custody without incident.

Troopers also responded to Glenn Street in Dover Air Park and executed a search warrant on a vehicle belonging to Mr. McDonald. Police said 1.8 pounds of marijuana were found there.

Mr. McDonald was charged with possession of a controlled substance, possession of a controlled substance in Tier 1 and 3 quantities, possession with intent to deliver a controlled substance, tampering with physical evidence and second-degree conspiracy, along with two counts of possession of drug paraphernalia. He was arraigned in Justice of the Peace Court 7, Dover, and committed to Sussex Correctional Institution, Georgetown, on a $136,200 cash bond.

Ms. Carter was charged with possession of a controlled substance in a Tier 3 quantity, possession with intent to deliver a controlled substance in Tier 3 quantity and second-degree conspiracy. She was arraigned in JP Court 7 and given a $40,600 cash bond. She was held at Baylor Women’s Correctional Institution, New Castle, according to the Delaware Department of Correction.

Ms. Evans was charged with possession with intent to deliver a controlled substance, second-degree conspiracy and possession of drug paraphernalia. She was arraigned in JP Court 7 and released on her own recognizance.

Mr. Brown was charged with possession of ammunition by a person prohibited, possession with intent to deliver a controlled substance, possession of drug paraphernalia, second-degree conspiracy and criminal impersonation. He was arraigned in JP Court 7 and committed to SCI on a $23,100 cash bond.