Four suspects have been arrested and charged in three unrelated homicides that occurred in Washington during the past three months, D.C. police reported yesterday.

Two suspects were charged with homicide in the death of Theresa Lockley, 65, of 4215 3d St. NW, who died of asphyxiation early this month after being tied up and gagged in her home. Police identified the pair as Jerold T. Savage of 325 Varnum St. NW and John H. Liles, 21, of 12709 Radburn Pl., Oxon Hill.

Officers said that Daryl A. Gaskins, 20, of 407 50th St. NE was arrested and charged with homicide in the June 26 stabbing death of Lonnie B. Ferguson, 38, of 257 56th Pl. NE.

Last Friday, D.C. homicide detectives arrested 19-year-old Horace Williams of 1430 W St. NW and charged him with homicide in the April 24 shooting death of businessman Hae Im.

Im, a Korean immigrant who owned the Swann Market at 1820 15th St. NW, was shot to death April 24 during a robbery at the store.

Police said members of the Korean Businessmen's Association and residents of the community around the store raised $2,000 in reward money, and the Police Crime Solvers program offered another $1,000. Williams was in D.C. Jail awaiting trial in connection with a separate charge of assault with intent to kill when he was charged.